Luke didn't try to kill, just, if anything, to injure the man and stop him hurting anyone else. His lightsaber flashed in the sunlight as he moved forward to engage. Of course, being an energy blade, it easily sliced through the metal of the earth-made sword. Luke took care with the strength he used, pushing the green blade just enough to slice the metal but without going to far and into the man's body.

He wasn't fond of it if it wasn't necessary, but decided to employ a little Force persuasion.

You want to turn back and leave. It will only lead to you being harmed and possibly killed if you stay. You will be helped so this can be avoided. he said, reaching a little into the bandit's mind with the Force. Of course, if he were strong minded enough, it might not work, but it was worth a try.